Copying and enlarging camera



J. BECKER.

COPYING AND ENLARGING CAMERA.

- APPLICATION FILED JAN. IB, 1917. v 4

1,339,090. Patented May 4, 1920.

fm/ 3 SHEETS-SHEET l. if I4- /13 J. BECKER.

COPYING AND ENLARGING CAMERA.

APPLICATION FILED IAN. I8. 1917.

Patented May 4, 1920.

3 SHEETS-SHEE'T 2.

TABLE oFDIMENSIONS m 'me F ULLY ADJQSTED nu REGUIRTED CHMERMEgsJandZ o Io 2.o 3o 40cm J. BECKER.

COPYING AND ENLARGING CAMERA.

APPLICATxoN FILED 1AN.1B.1917.

1,339,090. l Patented Muy4,1920.

3 SHEETS-SHEET 3.

' Cameras, of Whichthe following is a speci- .unrrnn smarts PATENT' OFFICE.

JOSEPH BECKER, OF 'WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

COPYING AND ENLARG-ING CAMERA.

Specification of Letters Patent.

Patented May 4, 1920.

Application filed January 18, 1917. Serial No. 143,085.

.citizen of the United States, residing, at

Washington, in the District of Columbia, have invented certain new and useful I niprovements in Copying and Enlarging ication.

The presentl patent application is identified, for convenience .of reference in my related applications, as Case At. t

The present specification hereinafter makes specific references to my related applications or patents, as follows: Case A, now latent 1,178,474; Case l, now Patent 1,103,342; Case O, now Patent 1,103,343; Case T, now Patent 1,142,295; Case ll, now Patent 1,190,214; Case Y, Serial No. 732,488, filed November 20, 1912, now continued as ('ase Au; Case Ab, now Patent 1,178,477; Gase Ae, Serial No. 66,371, liled December' 11,1915; Case f,'no\'v Patent 1,178,478; the above mentioned kCase Au or continuation of Y, now latent 1,289,088.

rlhe invention consists in an entirely novel type of focuser which is specially adapted for use with copying or enlarging cameras and to which I' have already referred (in describing Figures 10 to 15 of my said Case Ae), as a single sight optical focuser to distinguish it from the normal or double sight `optical focuser, typiied, for instance, in Fig. 3 of my said Case A.

A single-sight focuser can only be used` in a copying or enlarging camera, but it differs radically from the mechanical focusers of my said cases K, O, T, U, and Y or Au, in that it does not automatically focus the camera, for it on the contrary leaves the three camera frames O, L, I entirely free; but it does automatically point out or indicate, at all times the exact focall optical focuser of the radial cam type in which the basic or sector angle delta (A) is variable, and adjustable, as in my said Case Y, but the adjustment here serves to permit of setting the basic angle at any value that may, under present conditions, be necessary to suit any one of different lenses. Different lenses, under present conditions, require different basic or sector angles delta (A), in the focuvser, in all cases where the substitution of one lens'for another, on the lens frame li of the camera. changes the horizontally measured distance of the outer focal ,plane l" of the lens from the said lens frame L.

rlhe accompanying drawing shows a form of the invention inwhich the focuser is mounted on top of the camera, because this .form Vis most easily described and understood. ln current practice, the focuser should preferably be mounted on the side of the camera as in Fig. 18 of my said Case A, because this arrangement is not only more compact, but generally more convenient. y

Fig. 1 is the vertical meridional section of a copying or enlarging camera, comprising a very simple but fully operative form of my invention, having all adjustments needed to permit of adjustingl and regulating the focuser so that it will operate in exact S-and-all-point correspondence with any one of dierent lenses; but, shown as being properly adjusted and regulated for the given lens 9 seen in the ure; and showing the focuser, moreover, in one of its focus-indicating positions; that in Awhich the diametral object-to-image ratio is 2 to 5.

Fig. 2 is a diagram of the four essential material elements of Fig. 1, to wit sector delta (A), lens 9, screen 4. and screen l, all placedv and spaced as in Fig. 1, but with the additional imaginary dots and lines that are needed in giving a full explanation'of the exact geometrical principles involved.

Fig. 3 is the scale for line dimensions in Figs. 1 and 2.

Fig. 4 is a'table of all the fundamental -angle and line dimensions occurring in Figs.

1 and 2.

Fig. 5 is a view, similar to that of Fig. 1, but illustrating the final phase of adjustment number one, which is made on left infinity, for automatically determining that special value of the sector angle delta (A) which is required to secure correct operation of the focuser with the particular lens 9 used.

Fig. 6 is the scale for line dimensions 1n Fig. 5. t ig. 7 is another view slmilar to that of Fig. 1, but illustrating the final phase of position of groove 42 on frame Q, which determines the rectilinear locus 42 of pintle V on frame (i), for all lenses differing in focal length, but having the same identical external principal focal plane FZ.

Fig. 8 is a third view similar to that of Fig. 1, but illustrating that particular phase of adjustment number three which immediately precedes the last step, or insertion of pintle V, and which determines the exact position v that must be occupied by said pintle as predetermined by the focal, or f length, value of the particular lens used..

Fig. 9 is the scale for line dimensions used in Figs. 7 and 8. v

Verification by scale and by computation is facilitated by the selection of whole number values for all linear elements, and such selection was facilitated by making the basic angle epsilon prime (e) of such value that its cosine is exactly equal to minus three-fourths, as indicated in said table,

Fig. 4.',

he value of the angle epsilon prime (el itself is given in the table, Fig. 4, in two different forms. It is first expressed in degrees, minutes, seconds, and tenths of seconds as 138 35 25.4, and it is again expressed, more simply and more clearly in decimal form, as 1.5399 Q, which is its value in quadrants or vright angles.

The quadrant or right angle is the angular unit already used in my said Case Y, now Au and in my said Case Ae. Y

The accuracy of the drawing hardly warrants the use of more than three decimal places in the quadrant value, 1.5399 Q; butthe numerical values are, nevertheless, given as fully as they are, merely to emphasize the fact that the basicangle is as arbitrary in value as may automatically be predetermined bythe optical dimensions of the-particular lens used.

My copying or enlargin camera' comprises a table 10 with two rai s, such as 11, to form, on top of table 10, a suitable guide way for a camera OL. This camera OL is Separately usable as a view or tripod .as seen in A vertical screen I, rigidly mounted at the the pivot D of a sector 14. This camera, and to this end it has its base 12 provided with a threaded aperture 3 which 1s adapted to receive the tripod screw 64,

Fig. 7.

extreme right hand end of the table 10, con- `stitutes the third-or image frame of the combination.

The lens frame L is provided with a vertical extension or post 13 which supports 75 13 also supports a small bracket 5, t rough which is threaded a screw 6 which is adapted to engage and press against the narrow cylindrical edge of sector 14 to lock the so sector against rotation as desired whenever the focuser is being regulated and adjusted, as explained later on, for use with a given lens.

Sector 14 has a rigid radial arm 16 with a 85 radial cam slot 17 adapted to have sliding engagement with the object frame pintle V; and it has an angularly adjustable arm' 16', whose inclination delta (A) to arm 16, may

be fixed at any desired value by means of a projecting end of pivot D acting as a peep sight, and the radial line of sight 17 thus determined, constitutes the single sight of the combination.

The object frame O is grooved at'3() to form a slideway for a metallic fixture 3l, 3.2, 33, whose horizontal web 31 is slotted and traversed by a screw 34 which serves to clamp the fixture in any desired longitudinal adjustment on the said object frame O.

The fixture .31--33 carries a stud T on which is pivotally mounted the arm 40, and this arm 40 has a clamp screw 41 which passes through arm 40, into a nut that has sliding `engagement in-an arcuate undercut groove 36 formed in wall 33 of the fixture, so that arm 40 may be firmly clamped and rigidly held at any desired inclination, which, for present purposes, is best measured by the obtuse angle epsilolrthird (e The arm 4() is provided with a straight radial undercut groove 42 which also admits a nut into which engages the cylindrically reduced and threaded end of the ob'ect frame terminal or pintle V. Terminal V may accordingly be clamped to arm 40 at any desired radial distance TV from pivot- T, and in this way the distance ZD of its zero position Z from point D may be made of any value imposed by the focal length fof the particular lens to be used.

The fixture 31-33 has its rear vertical wall 32 perforated at 37 to form a peep, but stud T really serves as a peep sight proper when the-device is. used as a double-sight focuser. Coperating with 37, as bead sight, is a pin or stud U which is fixed in upright 13 at the same level as T and 37.

lWhen the device has been properly adjusted and regulated, and the focuser larm DS points at V, as in Fig. 1, all of the equations given in the table, Fig. 4, are satisfied. Y I

Before proceeding to adjust and regulate the device for use with any given lens, we must first' locate and permanently mark pointV on the image frame I in direct horizontal alinement with sights 37 and U.

When point V .has once been located, there is no further use for the horizontal sight linel T U, except when the camera part OL is removed for use on a tripod. as in Fig. 7, for then V is no longer present ex- -cept as some unknown point in the object to be photographed, and this unknown cpoint must be discovered by sighting along TU, substantially as explained in my said Cases -A and Ae in connection with the double sight focusers there disclosed.

V being therefore determined and disr tinctly marked on the image plane PV, we may adjust and regulate the focuser for use with any one of different lenses, substantially as first explained at length in my said Case K, by means of three independent focusing operations. l

The lens to be used is mounted on frame L in any preferred manner. This fixes the position of the outer focal point F as well as the position ofthe imaginary lens frame point Z', which represents thezero position of the image frame terminal V.

Moreover, as D is also a lens frame point, the basic angle epsilon prime (a) is also seen to be predetermined by the simple operation of mounting the lens 9.

Now, the sector angle VDS or delta (A) `must be` made equal to the basicA angle epsilon prime (e) and this first structural adjustment is determined by focusing on, as in Fig. 5, left infinity.

The angle VTE or epsilon third (am) must also be made equal to epsilon prime (e), and this is done byfocusing on right infinity, as illustrated in Fig. 7.

Finally, the radial distance TV, or rather ZD minus DZ, must be determined by focusing the end frame O on the end frame T at any preferred finite distance, as illustrated in Fig. 8. t

A detailed description of these three separate adjustments will now be'given.

Adjustment 0.-1, 0n left hand inynzty.

Remove pintle V to free the sector14 and thenset the' sector 14 S9 that its radial arm 16 shall point as in Fig. 6 to left infinity and temporarily fix it, in such position, by means of the clamp screw 6.

Remove the object plane, screen, or negative 4, to admit parallel rays 21, 22, 23 from left infinity, directly through the object frame O, to the lens, and shift the lens frame 'rectly at V', and finally clamp it to sector 14 in such position by tightening screw l18. This has made the sector angle (A) exactly equal to the basic angle epsilon prime (e) and completes the first adjustment.

Screw 6 may therefore be turned down to free the sector 14 andprepare for adjustment No.2, which involves'focusing on right hand infinity.

Adjustment N o. `2, `0n right hand injnz'ty.

This'is most easily performed on atripod. Hence, first mount the camera OL, as in Fig. 7, on a tripod 60 tol 64 and sighting along TU, pick out an object point at right-hand infinity, as test object, and as a substitute for the present mark V. The ray from such object point at infinity tohthe eye at E-is indicated by arrow 51. Other parallel rays from the same object point are indicated by arrows 52, 53, 54, 55.

Now turn disk 14 until the sight line DS points on the same said object. This sets DS parallel to TU; and to hold it firmly in this position, the screw 6 is again screwed up against sector 14, as indicated in Fig. 7.

A focusing screen 4 is now inserted in the object frame O, to be set in focus on the same infinitely distant test object, or on the parallel rays 53, I54, 55; and as this practically reduces PF to zero value, as shown in Fig. 7, the object frame is temporarily clamped to-base 12 in its thus determined zero position.

The two clampscrews, 34 and 41 are now loosened so that arm 40 may be freely brought up into the position--ofFig 7 ,where it registers exactly in position and inclinaltion with radial arm 16, so that its inclina- Adjustment N 0. 3, at d finite dstume.

' The camera bed 12 is temporarily clamped to the table 10 in any preferred position, such as that seen in. Fig. 1, 'and the object frame O is moved back from F to P through It is therefore a distance FP, which is equal to 12 centimeters in the case illustrated, to set it sharply in focus on the image frame I, and it is also temporarily clamped to its bed 12, so that the three` camera frames, to wit: object frame O, lens frame L, and image frame I, are all three positively held in proper focal relation. In such case the properly adjusted sight line -DS should point at V. The sector 14 is therefore turned until DS does point exactly at V as shown in Fig. 8, and this proper inclination of the sight arm DS is fixed by bringing screw 6 a third time up against sector 14:, also as shown in Fig. 8.

The radial cam slot 17 now crosses the slot 42, in arm 40, at a certain point e which is the position that should be occupied by pintle V.

Pintle V is therefore inserted and firmly fixed to arm 40, in its thus determined permanent position.

Screw 6 is again loosened and this completes the third adjustment.

The combination is now ready for use either as a copying camera with single sight focuser or as a tripod camera with a double sight focuser, and the operation in either capacity is perfectly obvious.

The advantages of a single sight focuser over the mechanical focuser of my Case T,

for instance, is that the three frames O, L, I, of the camera, may be moved in any manner and set in any desired relative position, as freely as if no focuser were present; but the single sight line 17 will at all times indicate automatically to what extent and in what direction the camera Vmay be out of focus; and how it may generally be brought linto focus in either preferred one of two different ways, to wit: by moving the camera OL as a whole along on table 10; or, secondly, by simply moving the object frame O alone.

Theory of the correctly regulated foeuser.

The three adjustments described above, by their combined and properly ordained actionv have accomplished two positive things, to wit: first, they have fixed the henceforth invariable value of the sector angle delta (A); secondly, they have fixed the henceforth invariable relative position which is occupied by intle V, with relation to the object frame It only remains to be proved that there has been established between the focuser, in its focus-indicating positions, and the lens 9, that exact S-and-all point correspondence which I first disclosed in connection with the theoretically exact optical focusers seen in Figs. 1, 2 and 19 to 22 of my said Case A. (See particularly, in my said Case A, the conclusion on page 11, lines 20 to 24.)

The following proof, though long, has the advantage of being entirely independent of The fulcrum yof the bent lever 16, 16' is marked as two points D and D', corresponding Vto the two points C and C of the rectangular radial cams Figs. 12 to 20 of my said Case U; also to the two points A and A in Figs. 4 and 17 of my said Case A.

Omitting W as a purely secondary optical point, Fig. 2, therefore, really shows sixteen important and separately identified structural for geometrical points, whichmay'be distinguished as: First, the three objectframe points P, V, T, which are relatively fixed, but together movable with the objectframe O, as fixed points of said objectframe; secondly the eleven lens-frame points D, D, K, ic, N, N', F, F', z, z', z", which are all relativel fixed, but all movable together with the ens frame A, as fixed points of the said lens frame; thirdly, the two image frame points P., V, which are relatively fixed, but both movable together with the image frame I, as fixed points of said image frame.

In the present, or Fig. 1, embodiment of my invention, the ima e frame I is normally stationary, and the ot er two frames L and O are movable.

It is easier however, as in my said prior Cases K, O, I', U, to conceive all displacements as they would be in those forms of the invention which have the lens frame L stationary.

Assuming, therefore, in Fig. 2, that the lens frame L is, and always remains, stationary, the eleven lens frame points D, D', K, K', N, N', F, F, Z, Z, Z, will all be stationar and, the five end-frame points P, V, T, V', will alone be movable.

This distinction is graphically made clear in IF ig. 2, by lrepresentin the five movable end-frame points, P, V, P', V as perforated or wheeled dots, to indicate motion; whereas, the eleven lens frame dots are all shown as unperforated or black dots, to indicate fixedness. j

The double pointD, D', and the projection K of D on the horizontal line of sight are structurally predetermined, and absolutely invariable, for any lens that may be used in the camera.

After a given lens 9 has been mounted as explained above, its four cardinal points, F, N, N', F', are likewise fixed, and. it 1s noted that inthe present case the distance z of the nodal point N from the vertical plane DK' is`1.5 centimeters. This offset z may have any plus or minus value, and it may even accidentally be ml; but as indicated in the figure, its value is quite arbitrary, except in so far as such value is automatically predetermined, as in the present case, by the optical dimensions of the particular lens used.

The vertical plane through the outer principal focal point F meets the horizontal sight line TV in Z. Hence the mere act of mountin the lens 9 has predetermined, first, the location of point Z secondly, the length of the base line ZD; thirdly, the inclination epsilon prime (e) of the base line ZD.

It has likewise determined the location of point Z, which is the zero position ofpin T, for the distance of Z from K must equal the distance of Z from K. It has furthermore determined the location of Z, or zero position of V, becausepoint Z must be on DZ, and the product of ZD.DZl must equal the square of the focal length of the lens. The inclination of ZD is most conveniently measured by the obtuse angle epsilon prime (e), because the sector angle delta must equal epsilon prime (e), hence. the value of the sector angle delta (A) is likewise predetermined, and all elements of the focuser, that is to say all of its adjustable dimensions both linear and angular are predetermined by the simple act of mounting any given lens on the lens frame L.

All necessary and sufiicient structural conditions are summed up in the tabular equations that are noted in Fig. 4, and they have all beensatisfied by the adjustments described above.

By focusing on left infinity, as in Fig. 5,

the sector angle delta (A) was made equal to the basic angle epsilon prime (e).

By focusing on right-hand infinity, as in Fig. 7, the angle epsilon third (am) was made equal to' the sector angle delta (A),

and, as the delta (A) had previously been made equal to the basic angle epsilon prime (e), the groove 42 has exactly been set antiparallel to the base line ZD. Angles epsif lon second (5) and epsilon (e) of Fig. 2,

being necessarily equal to angle epsilon third (am), are likewise fixed by the same operation. After completion of the adjustment seen in Fig. 7 therefore the equality of the five different representations of the basic focuser angle is insured, or, in symbols,

'ment with V the position fv of pintle V was located, and V could be xed in its proper relative position with relation to the object frame O.

In the diagram Fig. 2, the base line ZD and the anti-base line DZ are anti-parallel with reference to the horizontal 7i. It', and it is convenient to conceive of these two lines as representing the two knife edge forming faces of a wedge that serves as a ful ZDZKK, for the bent lever 16, 16.

The bent lever 16, 16 in any given position determines two triangles ZVD and ZDV, which vary in shape and size, but which are always similar because their corresponding angles always remain equal, that is to say eze i (l) The angle epsilon (e) at Z and the angle epsilon prime (e) at Z are equal as `the result of adjustments 1 and 2, and they are invariable because they remain equal to the sector angle delta (A).

The other two corresponding angles of these triangles are variable; but they remain respectively equal, as need only be proved for one of them, the angle omega,

and by multiplication rezo The third angle phi, phi prime (q), qa) of the two triangles ZVD, ZDV could, if necessary be proved equal in similar manner; or, more simply, by noting that two triangles which have two angles equal must have the third angle equal to make up the sum of two right angles.

The triangles ZVD, ZDV having their corresponding angles equal in all positions of the bent lever 16, 16 must always have their homologous sides proportional, so that the following equation VZ ZD (4) DZ Z V is always true for all inclinations of the bent lever 16, 16.

In this proportion, or equation 4, the two for the position of Fig. 1 but for all other` positions, for the following reasons:

means DZ, ZD are invariable; and the two extremes VZ, ZV are variable; moreover, the product VZ.ZV of the extremes is always equal to the product DZ.ZD of the means. But the last product isfj or Vf2 because the distance DZ has indirectly been fixed b adjustment number three of Fig. 8, W ere, after insertion of pin V, the product VZ.ZV is identical with PF.FP, and hence evidently equal to f2.

In Fig. 1, therefore, which is simply Fig. 8 with pintle V inserted,

ZD.DZ:VZ.ZV:PF.FPf2 l.(5) This equation 5 holds, however, not only Any displacement imparted to P is necessarily imparted to V so that in all positions of the object frame O PF=vz (6) On the other hand,lany change made in the distance FP is equally and simultaneously made in the distance ZV', hence for all values of FP.

f FP=ZV i (7) I In all focus-indicating positions, equations, 5, 6, and 7, therefore yield equal to KZ; thirdly on DZ plot Z by making DZ equal to the quotient of DZ into f2; fourthly, draw PV equal and parallel to FZ to locate V on the object frame O; fifthly, make sector angle delta equal to the basic angle DZV or epsilon prime (s).

This rule makes no reference whatever to arm 40 or groove 42, which are therefore seen to be of no importance, except during the process of adjustment and regulation, to permit of securing correct adjustment and regulation without knowing'the focal length or any other optical dimension ticular lens used. f

The fundamental vprinciple linvolved in .but as object frame of the par- VCD of Fig. 19 in my said Case U, where the angle DC D', 'corresponding to the present angle .ZD Z, is m2.

General remarks.

NOTE 1.-My first disclosure of a radial cam focuser with adjustable basic angle delta (A) was made in my said Case Y.'

NOTE 2.-The three adjustments, herein fully described' because of the peculiar features involved, are really the same in substance and principle as those already used 1n m NOTE 3.-When either end frame, O or I, is called the object frame, the other end frame, I or O, must be considered on the image frame. Thus frame O serves as image frame of the tripod camera OL, of the enlarger,

at I claim as myinvention and desire to secure by Letters Patent' is:

said cases K, O,T, U, Y Ab, Ae, 'and The combination with a photographic camera having a focuser of the radial cam type comprising: first, a radial arm pivoted on the lens frame of the camera and adapted to engage the plate or film-holding frame of the camera; secondly, a radial element for the object likewise pivoted on the said klens frame of the camera; thirdly, means connecting said first two radial'elements so that they shall rotate in constant angular relation; .such connecting means com rising a normally rigid unit com ose of parts whose relative position can varied to adjust the angular dimension of such unit and thereby Set the said constant angular relation or basic angle of the focuser at any desired value.

In-testimony whereof, I have signed my name to this specification., f

JOSEPH BECKER. 

